1
3 5
7 9 11
13 15 17 19
21 23 25 27 29
In which row 2015 would come?

• 1
  3 5 consider last element in this row 5 which is (row number)^2+1=(2)^2+1=5
  7 9 11 similarly, 11 (row number)^2+1=(3)^2+2=11
  13 15 17 19 similarly, 19 (row number)^2+1=(4)^2+3=19
  21 23 25 27 29 similarly, 29 (row number)^2+1=(5)^2+4=29
  
  consider 44th row=(44)^2+43=Last element is1979.So, 2015 can't be in this row.
  consider 45th row=(45)^2+44=Last element is 2069.So, 2015 will be in this row.
  
  So, 2015 will be in 45th row.
• 8 years agoHelpfull: Yes(43) No(0)
• 45th row
  
  let the total number of digits be n
  then 2015=1+(n-1)2 or n=1006
  
  let 2015 comes in 'm' th row
  now, 1st row contains 1 digit, 2nd row contains 2 digits, 3rd row contains 3 digits and so on
  and also sum of all digits in rows from 1 to m is 1008
  in other words 1008 is the sum of first m natural numbers
  therefore,
  m(1+m)/2=1008
  m^2+m-2016=0
  m=44.4
  so, 2015 comes in a row which is just after 44th row, i.e.,45th row
• 8 years agoHelpfull: Yes(5) No(0)
• n(n+1)/2 gives 44*45/2=990...then 1+(990-1)*2=1979 is the starting element..the row ll hold 1979+44 elements..so its on 44th row..
• 8 years agoHelpfull: Yes(1) No(2)
• 1979 s the last element sry guys....the nezt row 45th l contain 45 elements..so 2015 i in 45th row
• 8 years agoHelpfull: Yes(1) No(2)
• Ans is 45th row
• 8 years agoHelpfull: Yes(1) No(2)
• 45 is rt answer
• 8 years agoHelpfull: Yes(1) No(2)
• i think ans should be 15
• 8 years agoHelpfull: Yes(0) No(3)
• typing error sorry it should be 14.
  
• 8 years agoHelpfull: Yes(0) No(3)
• All options of answers of this Question are more than 44.
  
• 8 years agoHelpfull: Yes(0) No(3)
• mene 44 tick kiya and dnt knw its right or wrong
• 8 years agoHelpfull: Yes(0) No(3)
• answer is 45th row.
• 6 years agoHelpfull: Yes(0) No(0)